125+mph in the Marauder

[Zack]

This is my first post, great site by the way. To start off, I want List my Mods so far...
4:10 Gears
Reinhart Chip & Plugs
Flowmaster 2 Chamber Mufflers
Factory Spoiler
35% Tint
Let me say that this is how the car should have left the factory!
Thanks Dennis.
Now onto business...
Im getting on to I-80east last night when I spot a Mustang GT coming up fast. What better way to test out the marauder at high speeds than racing a car with the same motor and trans. So we both nail it and the marauder takes off like a bat outta hell! All the way to 130mph, we stayed side by side. Thats pretty good for the heavy Marauder. So with the good news off to the side, here is the bad.
At about 125 mph I felt a horrible vibration an attributed it to the driveshaft problem everyone is talking about. So I backed off the gas and had to watch the mustangs flashers pierce my eyes. I hate that ****.
Anyway, the huge smoke cloud soon followed behind the car. By this time im furious but close to home. With no driveability problems, I nursed the car back home a short distance away. When the morning finally arrived after a sleepless night, I ***esed the problem. Are you ready for this? The Output seal on the Tailshaft of the trans came completely out of the trans and was sitting around the driveshaft! Hows that for bad luck. Anyway, talked to my guy at the dealer and he was not at all surprised. He said that 2 years ago, the police cars were recalled for the same problem because ford increased the gear ratio of the rear end from 3:27 to 3:55, but did not upgrade the driveshaft to compensate for the higher rpms it would be turning. Dennis also told me a similar story and said the driveshaft starts to 'boomerang' at such high speeds and can pull the seal right out of the tailshaft, or break the tailshaft. Well, the Marauder is down for a week until My Metal Matrix Driveshaft comes in thanks to Dennis Reinhart. That man has been nothing but good help to me and the Marauder. I hope this doesnt happen to any of you guys out there. Ill keep you guys posted as to how it turns out
Zack
Homewood, Il

[Fourth Horseman]

Wow. Thanks for posting your story. Looks like i'm keeping it to 100 or under until I get around to the DR mods.

[drobin]

Zack, what a bummer!!! Sounds like trouble brewing for the rest of us who don't yet have a Reinhard drive shaft. Oh well, back to the cookie jar I go.........

Thanks for the info....

Donald

[SergntMac]

Sorry for your bad news, Zack, but thanks for posting. After only one high speed run, eh? Wow, that's a lot less tolerance than I expected. I don't plan on much high speed driving, but if once is all it could take...

Note to Xmas list...Dennis drive shaft.

[Murader03]

Here's a head ache that shouldn't have happened. It's been cussed and discussed all over this board about the drive shaft vibration. It's been stated that this was the reason the car was speed limited to 117mph, or there abouts. When you installed the chip, the limiting was removed allowing you to reach the speed of self distruction. Sorry it had to happen, but at least you were close to home and the tranny wasn't damaged in the process. You can bet that if you had taken this in for warranty coverage, the dealer would be looking for the reason why and would fine the chip, thus voiding your warranty on whatever was destroyed. We are all going to have to be careful as to what we do after the chip install. We don't want to draw to much attention to the mods we are doing. SHW and Dennis have both made note of this on the board.

[Heavy351]

Even after you get a Reinhard driveshaft you might want to consider a driveshaft loop. Consider it a $40 insurance policy in case something really lets go at 125mph.

I feel better having one.:)

[drobin]

Heavy, exactly what is a drive shaft loop and where do you obtain one if its what I think it is.....

Donald

[Heavy351]

A driveshaft loop is a metal ring that surrounds your driveshaft near the transmission. The idea is that if you break a U joint or the shaft itself (unlikely) the loop holds the flailing driveshaft above the pavement and prevents it from pole vaulting you in some direction you did not want to go at 125 MPH.

Saw a video of it once.. dragstip + lots of traction + lots of torque + stock U joint = end over end. :eek:

Jegs, Summit, or any speed shop should have one for less than $50.

I think somebody here with a supercharger already has one.

I could be nutty, but I like knowing it's there.

[Fourth Horseman]

I don't think that's nutty at all. I like to play with my car, but it's not worth getting killed for, you know?

[mensrea]

Why would you spend over 400 bucks on a driveshaft when ford makes a metal matrix composite shaft that is used in the police interceptors.... it bolts right in and has NO vibration.

you can pick one up for $200 or less.

Here's the part number

XW7Z-4602-AA

[Dennis Reinhart]

Well, first of all lets not overreact, this is the first time that this has happened and there could be several reasons for it happening. One it could be that the drive shaft was out do to the installation of the 4:10 gears, and it could have been corrected by indexing the drive shaft, Two he could have just had a bad shaft, Three he may have had improper installation of the gears, there have been lots of other members here that have installed the 4:10's and not had this problem??? so again, in this case I have sent him the MMDS.

Ford used to install the MMDS for police cars, now all they install is the aluminum. The MMDS drive shaft exceeds the specifications for the aluminum drive shaft in strength balance and quality, so again lets wait and see how his car reacts with the new shaft and that may prove it was another problem. And not the shaft at all.

[mensrea]

The part number I posted is for the MMDS (MMC) shaft, Ford still produces it, they just don't include it in new cars. This is what I put in my car and have had ZERO problems... and remember I am pushing much more torque and horse than stock.

[Pantherman]

The important thing here is something called "critical speed". Every rotating shaft has some critical speed at which it will whip and vibrate violently. My old references say critical speed equals about 4,700,000
times the square root of the sum of the OD squared plus the ID squared, divided by the length squared. The 4,700,000 number is a constant made up of things like moment of inertia, modulus of elasticity, and shaft mass per unit length. Aluminum improves this number slightly, metal matrix aluminum is even better, carbon fiber is better still but very expensive. Using good engineering practice, Ford will only allow about 75 per cent of the calculated number. Don't hold me to my quick and dirty calcs, but considering all these things, I come up with a fairly safe critical speed of about 6060 RPM. Sooo--if you are showing over 6000 RPM in third gear, you are getting into a gray area where a slightly imbalanced/nicked/bent/misindexed shaft could hurt you badly. To learn more, just do a google.com search on driveshaft critical speed.

[Larry Vogel]

Hope your insurance agent isn't reading this!

You guy's doing this type of speed on the streets are putting yourself's and the public at risk. Go to the dragsrtip, that's what they are their for, if they aren't open wait till they are, they have safety crews for any mishap you might have.

[tetsu]

Mensrea, Kenny didn't have to shorten it? I was under the impression
our shafts were shorter.

Johnny

[mensrea]

The tailshaft we have on our cars is identical to the tailshaft housing on the 99-00 PIs, so the drive shaft bolts right in.

[tetsu]

Wow. Why in the hell did they use a lousy aluminum shaft then??!?!?!?!

That blows my mind.

Johnny

[mensrea]

It's my understanding that although Ford has enough to stock for parts, they could not secure 18,000 shafts a year